Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
dinh tai » dinh toai, dinh tri, dinh thi
co sach » bo sach, cuon sach
tai cua » thai cua, tai cuc, tri cua
va dinh » van dinh, va kinh, va tinh
cac tac » cac toc, cac bac, cac dac
cac tuc » cac toc, cac tu, cac nuoc
hieu va » lieu va, hieu qua
hang xa » hoang xa, hang va, hang ca
ly hang » ly quang
cua tre » cua te, cuu tre, cua triet

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((co sach) or (hoc sach)) ly hang xa hoi. hieu va ((cac tuc) or (cac tac)) va dinh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((co sach) OR (hoc sach)) ly hang xa hoi. hieu va ((cac tuc) OR (cac tac)) va dinh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((co sach) or (hoc sach)) ly hang xa hoi. hieu va ((cac tuc) or (cac tac)) va dinh tai cua tre*.